Prior to Word War II, the vast majority of swimming pools were public pools or private group owned facilities. Since that time, and mostly in the past thirty years, residential swimming pools have become increasingly popular so that the number of swimming pools in the United States has grown dramatically. Swimming pools were formerly made with forms and poured concrete but formless construction, wherein the concrete is sprayed in place over a pre-assembled matrix of reinforcing bar, has reduced both the cost and construction time. Where once, virtually every pool had required a custom made circulation and filtration system, packaged units became available in a range of sizes, so as to allow additional savings. These economies, together with price competition among the installers, served to accelerate growth of the swimming pool industry. Inasmuch as the need for routine maintenance tends to discourage prospective pool buyers, maturation of the industry has been marked by the advent of labor saving devices such as automatic surface skimmers and self operating pool vacuums.
Maturation of the industry is accompanied by more intense competition among the pool installers. In a typical scenario, a pool installation company will subcontract the specialized construction phases, excavation, re-bar placing and tying, concrete spraying, tile work, plastering and decking to subcontractors. Construction methods are virtually standardized in the industry and often, the same sub-contractors will work for several pool installation companies. As a result, the cost basis for similar products of similar quality is much the same to all installers and each of them is driven to control internal operating costs and shave profit margins in order to remain competitive. Sub-contractor supervision and quality control are the factors which management can control. Since sub-contractor supervision is purely a management skill, to which all have equal access, the labor of plumbing and pool equipment installation and the efficacy of quality control are the only areas where a competitive advantage may be achieved. Therefore, there is a continuing need for refining and improving these operations.
In recent years, homeowners, municipalities and commercial entities that opt to install a swimming pool have a wide array of features available for selection. These features range from complex water features such as fountains and spas in which the water circulation system includes structures that allow water to cascade down rocks or other materials. An owner may also opt for various lighting features that enhance the owner's swimming and leisure experience in the evening. Today, a pool owner is limited only by the imagination in terms of the water and lighting features that may be installed.
Regardless of whether a customer desires the ultimate backyard oasis or a more traditional lap pool, numerous receptacles necessary to carry water from and return water to the pool for filtration and circulation is necessary. These receptacles, such as the pool's drains and water return heads are common. Drains are found at the bottom of the pool structure and water return heads may be found on the bottom of the pool or on side walls. To facilitate effective water circulation, many return receptacles are situated throughout the pool.
As part of the construction process, the plumbing for carrying water away from and to the pool is installed. This takes place after excavation, but before re-bar placing and tying and concrete spraying. Once the plumbing, typically in the form of PVC is in place, re-bar is placed and tied and concrete or gunite is sprayed. After the concrete is sprayed to form the walls and floor of the pool, concrete near and around the drains and return receptacles must then be removed to permit the plumber access to later install the necessary fittings on the pipes for final installation of the drains and returns. Once removal is accomplished and the fittings are placed, the voided area is filled in again any particular type of water proofing membrane around the fittings to prevent the fittings from leaking. To accomplish the removal process, installers roughly carve out with a trowel or other tool an area that provides this access. The problems associated with this approach to providing access are many. First, the installer charged with removing the concrete does so at his own discretion in terms of the width and depth of the void left in the concrete. This presents a problem as every such carve out for the drains and return receptacles compromises the strength and water retaining capabilities of the swimming pool. The lack of a predictable carve out can also increase the risk factor of allowing oxidation to occur within the steel structure. If any steel is exposed for a prolonged period of time, oxidation may occur. If this were the happen, the only solution is to saw cut and remove any and all oxidized steel, leading to an unsightly patch that undoubtedly result in an irate customer. In addition, when the carved out area is excessively large, gravity works against adequately refilling the space as the water proof membrane in the upper half of the void will tend to slide down and out of the opening. Moreover, any gaps left below the PVC pipe and the outer surface of the cavity may not be refilled properly. This is because the pipe itself prevents the effective blowing in of the final interior finish. Ultimately, the carve out and replacement process is a necessary evil that is time consuming, subject to many imperfections and if not done properly may require the installer to repeat the entire process. Thus, there is a need for a product that promotes the predictable and reliable carving out of the concrete in areas that will receive plumbing fittings.
Another issue associated with pool installation is the phenomenon of ground water accumulating around and beneath the swimming pool structure. If a sufficient amount of water accumulates beneath the pool, the pool structure could be displaced or float above the ground surface. Such a displacement, even if only minimal, will require installation of the pool structure to start anew. In order to prevent displacement, it is the custom within the industry to install weep holes in the floor of the pool. These weep holes are essentially spaces in the bottom of the pool in which no concrete is placed during the construction process. These spaces or voids may be one foot or less in diameter and provide an opening through the bottom of the pool to the ground. If during the construction process underground water forms or seeps to the area in close proximity to the pool, the water will enter the pool through the weep holes, rather than cause the pool to be displaced or float. Essentially, these weep holes serve as a pressure relief mechanism that prevent water build up beneath the pool.
Once construction of the pool is largely complete, the weep holes are filled with a water proofing membrane and ultimately coated as is the entire inside of the pool with marcite or similar pool interior surface product. At this juncture, the weep hole is now plugged. Although the pool construction site is stabilized, the possibility still exists for the onset of underground water build up, either through the emergence of a spring, a water main break or other source of flooding. If such a circumstance arises post-construction, the weep hole plugs will pop, permitting entry into the pool of the underground water, rather than structurally damaging displacement or float of the entire pool.
Much like the aforementioned carving out of concrete around PVC pipes to allow installation of plumbing fittings, the manner in which the weep holes are prepared and maintained during the installation process varies. Some manufacturers simply leave a round void at the bottom of the pool to serve as a weep hole. The problems with this practice are two-fold. First, a weep hole left uncovered during the installation process typically becomes filled with debris. In the haste to complete the construction process, the debris remains in the hole and is simply covered up with concrete or a water proofing membrane. As a result, a plug that should be eight inches in thickness may be only a few inches in thickness because of the volume in the hole displaced by the debris. Accordingly, the thickness of the pool at the weep holes is less than necessary to achieve adequate strength. Moreover, the thinner plug will “pop” under less pressure from even minimal underground water that would not otherwise impact the integrity of the pool walls.
Another common practice is to install a corrugated pipe within the weep hole that runs some distance underground. The ridges of the weep hole serve to grip the concrete later poured to fill the weep hole. The result is a stronger bond of the concrete within the weep hole, leaving the weep hole plug less likely to pop under minimal underground pressure. Even with the use of a corrugated pipe, however, the cylindrical shape of the plug is susceptible to premature popping and collection of construction debris. Thus, there is a need for a product that prevents debris collection and facilitates creation of a plug that is not susceptible to popping under minimal pressure.
Another issue commonly faced is once again steel oxidizing within the weep hole resulting in the weep hole to pop. In this event the pool must be completely drained down and the weep hole along with all oxidized steel to be removed. Once removing the weep hole it must be repacked with concrete or some sort of water proofing membrane. Due to the size and location of a weep hole at the bottom of the pool this patch is virtually impossible to cover up with out resurfacing the entire pool.
Another commonly faced problem throughout the construction process is the protection of the light fixtures themselves prior to the completion of the pool. The installation of all electrical components are normally installed in the beginning stages of construction leaving the new light fixtures exposed to masonry cements sticking or adhering to the fixtures. In the event that this happens countless energy and time is wasted on cleaning and detailing the lights prior to filling up the pool. Many practice the use of using acids to help dissolve the cements, but this stripping also destroys the light ring finish itself resulting in dull light ring finish. Protecting the entire light assembly throughout construction will avoid time and energy on the cleaning and detailing of the light prior to filling up the pool.
During swimming pool construction and water circulation system testing, the skimmer, pool drain and other plumbing receptacles are open and difficult to protect from the entry of dirt, concrete and other debris. The conventional practice of stuffing these receptacles with an empty sack does not resolve the debris problem. As a final step after construction and testing, the receptacles must be laboriously cleaned out by hand. Particularly at this time, there is a real risk of gravel, mortar, concrete or stones falling into the plumbing. Swimming pool pumps have a limited tolerance for ingesting such solids, and impeller damage or worse might result. An unfortunately sized rock might block a line at the first elbow it couldn't pass for an even worse and more expensive scenario. U.S. Pat. No. 5,978,978, assigned to Brian Claffey discloses a Method and Apparatus for Swimming Pool Construction.